The use of an overlap system for floating installation of flooring is available and readily known. U.S. Pat. No. 7,155,871, as shown in FIGS. 1-4, describes such a known flooring construction that utilizes a floating installation of numerous flooring panels.
The '871 patent describes a floor plank 100 having a top layer 114, a middle layer 116 and a bottom layer 118. Both the top and middle layers 114, 116 are prepared from flexible plastic, wherein the bottom layer 118 is prepared from flexible foam.
The floor plank 100, as a laminate, is prepared from an offset layer arrangement of the different layers. The top layer 114 extends an offset amount “a” beyond a long edge 132 of the middle layer 116 and a short edge 134 of the top layer 114 extends an offset amount “a” beyond a short edge 140 of the middle layer 116 to define an offset L-shaped marginal section 142 of the top layer 114. The marginal offset “a” is described as a matter of design preference, but is preferred to be approximately ¾ of an inch.
Furthermore, a long edge 146 (FIG. 1) of the middle layer 116 extends an offset amount “a” beyond a long edge 148 of the top layer 114, and a short edge 150 of the middle layer 116 extends an offset amount “a” beyond a short edge 156 of the top layer 114 to define an offset L-shaped marginal section 158 of the middle layer 116.
The L-shaped marginal section 142 of the top layer 114 and the L-shaped marginal section 158 of the middle layer 116 are of identical size and shape.
The floor plank 100 is sufficiently flexible, to conform to typical variations in surface contour of a floor base 102 (FIG. 2) upon which the floor plank 100 is laid. In addition, the flexible foam material of the bottom layer 118 is yieldable to small bumps and other imperfections in the floor base 102 generally referred to as surface irregularities. The bottom foam layer 118 thus enables the floor plank 100 to conform to such surface irregularities and lie flat on the floor base 102.
As shown in FIGS. 3 and 4, during installation of the floor planks 100 in side-by-side and end-to-end relationship, a downwardly directed adhesive surface 172 of the L-shaped marginal section 142 of the top layer 114 is positioned to engage an upwardly directed adhesive surface 174 of the L-shaped marginal section 158 of the middle layer 116 to form the assembly 80 of the floor planks 100. When placing two of the planks 100 together, one of the planks 100 can be angled at approximately 45 degrees with respect to the floor base 102 and onto the corresponding upwardly facing adhesive surface 174 of an adjacent floor plank 100. The floor planks 100 can be installed on the floor base 102 without mastic or an adhesive coating on the floor base 102, and without mastic or adhesive on an undersurface 188 of the bottom foam layer 118. Hence, during installation, the floor planks 100 are thereby assembled using a floating installation of numerous floor planks 100, and can be performed in any desired pattern.
During installation, the aforementioned planks 100 bear the possibility that the axes of two or more adjacent planks may not be properly installed parallel to each other. This creates a potential problem of open seams, which are not only optical defects, but create an issue of functionality for the prepared shiplap. Since open seams will not be tolerated, the plank must be removed. Once the adhesive connects two or more planks, the defective plank must be aggressively pulled from the connecting plank to correct the defective seam. As a result, one or more planks may become damaged resulting from the aggressive separation and minimal rigidity of the shiplap.
Additionally, the only force that holds two or more planks together is the adhesive applied to either the underside or top surface of the overhanging layers. As a result, in areas of high traffic, areas of high dynamic loading, areas of distortion and warping due to uneven and/or oscillating sub-floors the two or more connected planks may not be able to withstand shear forces. This effect is supplemented with an increase in temperature.